All three give the impression that taking a test helps with learning. It's fair to say the assumption is that we're talking about standardized variety, or some kind of hybrid multiple choice and extended response format.

Not so. Not even close.

The "test" we're talking about here is simply writing down everything you remembered after reading a for a given amount of time (I believe it was 45 minutes in the study). Free-recall. No multiple choice. No grading of the material. That was a more effective way of studying than putting together a concept map. That's what the study really looked at.